Author Correction: Amaryllidaceae alkaloids: identification and partial characterization of montanine production in Rhodophiala bifida plant.

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Amaryllidaceae alkaloids: identification and partial characterization of montanine production in Rhodophiala bifida plant.

Rhodophiala bifida (R. bifida) is a representative of the Amaryllidaceae plant family and is rich in montanine, an alkaloid with high pharmaceutical potential. Despite the interest in these compounds, many steps of the biosynthetic pathway have not been elucidated. In this study, we identified the alkaloids produced in different organs of R. bifida under different growth conditions, set up the conditions for in vitro R. bifida regeneration and initiated the molecular characterization of two R. bifida genes involved in alkaloids biosynthesis: the Norbelladine 4'-O-Methyltransferase (RbN4OMT) and the Cytochrome P450 (RbCYP96T). We show that montanine is the main alkaloid produced in the different R. bifida organs and developed a direct organogenesis regeneration protocol, using twin-scale explants cultivated on media enriched with naphthalene acetic acid and benzyladenine. Finally, we analyzed the RbN4OMT and RbCYP96T gene expressions in different organs and culture conditions and compared them to alkaloid production. In different organs of R. bifida young, adult and regenerated plants, as well as under various growing conditions, the transcripts accumulation was correlated with the production of alkaloids. This work provides new tools to improve the production of this important pharmaceutical compound and for future biotechnological studies.

Anti-inflammatory activity and chemical analysis of extracts from Trifolium riograndense

Abstract Aiming to investigate new therapeutic agents with fewer side effects, the number of studies about natural products has increased. Phenolic compounds comprise a well-studied class of abundant plant-derived compounds, whose anti-inflammatory activity has been described. Isoflavones are phenolic compounds that occur mainly in the Leguminosae family, and can be found in many species, such as Trifolium riograndense Burkart, Leguminosae (clover). In this study an HPLC method was used to determine and quantify four isoflavones (genistein, daidzein, formononetin, and biochanin A) in hydrolyzed leaf, flower, stolon, and root extracts of T. riograndense. In vivo anti-inflammatory activity was investigated using the rat paw edema method and in vitro chemotaxis model with a dry extract from the leaves, which had the highest amount of isoflavones. The major isoflavone found in all parts of the plant was formononetin. The chemotaxis assay revealed that the different concentrations (0.2-50 µg/ml) of the dry extract significantly inhibited neutrophil migration in a concentration-dependent manner (more than 90%). In the rat paw edema test, oral administration of clover extract 100 mg/kg was able to significantly inhibit the edema formation induced by carrageenan. In conclusion, chemical analyses showed that Trifolium riograndense is a plant rich in isoflavones and a new interesting option as isoflavone source. The results of the biological tests taken together show that the extract of T. riograndense has anti-inflammatory effect in rodents.

Disease modifying anti-rheumatic activity of the alkaloid montanine on experimental arthritis and fibroblast-like synoviocytes.

Montanine is an alkaloid isolated from Rhodophiala bifida bulb with potential anti-arthritic activity. In this context, we evaluated whether montanine has a disease modifying anti-rheumatic activity in two arthritis models and its effect in vitro on lymphocyte proliferation and on invasiveness of fibroblast-like synoviocytes (FLS). Antigen-induced arthritis (AIA) was performed in Balb/C mice with methylated bovine serum albumin, and nociception and leukocytes migration into the knee joint were evaluated. Collagen-induced arthritis (CIA) was performed in DBA/1J mice, and arthritis development and severity were assessed by clinical and histological scoring and articular nociception. Montanine was administered intraperitoneally twice a day. Lymphocyte proliferation stimulated by concanavalin A in 48h was performed with MTT assay, while FLS invasion in 24h was assayed in a Matrigel-coated transwell system. Administration of montanine decreased nociception (P<0.001) and leukocyte articular migration (P<0.001) in mice with AIA. In mice with CIA, treatment with montanine reduced severity of arthritis and joint damage assessed by clinical (P<0.001) and histological (P<0.05) scores and ameliorated articular nociception (P<0.05). In vitro, montanine inhibited lymphocyte proliferation stimulated with ConA (P<0.001) and decreased FLS invasion (P<0.05) by 54%, with an action independent of cytotoxicity. Our findings suggest that montanine can be further explored as an innovative pharmacological approach for autoimmune diseases such as arthritis.

Analysis of flavonoids in Rubus erythrocladus and Morus nigra leaves extracts by liquid chromatography and capillary electrophoresis

AbstractThis study uses high performance liquid chromatography and capillary electrophoresis as analytical tools to evaluate flavonoids in hydrolyzed leaves extracts of Rubus erythrocladus Mart., Rosaceae, and Morus nigra L., Moraceae. For phytochemical analysis, the extracts were prepared by acid hydrolysis and ultrasonic bath and analyzed by high performance liquid chromatography using an ultraviolet detector and by capillary electrophoresis equipped with a diode-array detector. Quercetin and kaempferol were identified in these extracts. The analytical methods developed were validated and applied. Quercetin and kaempferol were quantified in R. erythrocladus, with 848.43 ± 66.68 μg g-1 and 304.35 ± 17.29 μg g-1, respectively, by HPLC-UV and quercetin, 836.37 ± 149.43 μg g-1, by CE-DAD. In M. nigra the quantifications of quercetin and kaempferol were 2323.90 ± 145.35 μg g-1 and 1446.36 ± 59.00 μg g-1, respectively, by HPLC-UV and, 2552.82 ± 275.30 μg g-1 and 1188.67 ± 99.21 μg g-1, respectively, by CE-DAD. The extracts were also analyzed by ultra-performance liquid chromatography coupled with a diode-array detector and mass spectrometer (MS), UPLC-DAD/MS.

Genetic variability of isoflavones in the USDA red clover core collection

Red clover is one of the most utilized forage in agriculture and contains many of the isoflavones known for their human health benefits. The objectives of this study were: i) to quantify, using HPLC analysis, isoflavones in 77 accessions from the USDA core collection and a Brazilian line; ii) to verify possible relationships depending on their origin, improvement status or maturity type and; iii) to verify the seasonal variation. The isoflavone mean contents were 29.27 µg g-1 of dry material for daidzein, 163.69 µg g-1 for genistein, 11353.29 µg g-1 for formononetin and 6568.8 µg g-1 for biochanin A. Clustering was mainly influenced by the total amount of isoflavones and partially due to maturity type, improvement status and geographic origin. The seasonal evaluation demonstrated an increase of concentration during winter, and decrease during spring. These results highlighted accessions that can be used to develop new varieties with low or high isoflavones concentration.

In vivo and in vitro anti-inflammatory activity of red clover Trifolium pratense dry extract

Red clover Trifolium pratense L., Fabaceae, contains four isoflavones, mainly formononetin and biochanin A, and in smaller concentrations, daidzein and genistein. These compounds have gained a lot interest due to its human health benefits, such as estrogenic and progestogenic activities, antioxidant, anti-cancer and others. The objective of this study was to determine in vivo and in vitro anti-inflammatory activity of red clover dry extract. The in vitro anti-inflammatory activity was assayed by the technique using the Boyden chamber method, evaluating the leukocyte migration inhibition (chemotaxis). The in vivo anti-inflammatory activity was tested by a carrageenan-induced rat paw edema test. The results of anti-inflammatory in vitro test showed that there was a significant inhibition of leukocyte migration at the concentrations of 100, 50, 25, 10 and 5 µg/mL of red clover dry extract, these doses resulted in 94.73, 95.39, 94.73, 84.68 and 78.75 percent of inhibition for each dose, respectively. The anti-inflammatory in vivo test resulted in a significant activity in both tested doses (100 and 50 mg/kg of red clover dry extract) and at each tested time. The average percentage of edema inhibition was 63.37 percent. The findings of this study suggested that red clover extract might be suitable for the treatment of inflammatory diseases.

Lycorine derivatives against Trichomonas vaginalis.

Six lycorine derivatives were prepared, characterized, and evaluated for their in vitro anti-Trichomonas vaginalis activity. Compounds bearing an acetyl (2), lauroyl (3), benzoyl (4 and 5), and p-nitrobenzoyl (6 and 7) groups were synthesized. The best activity was achieved with lycorine esterified at C-2 position with lauroyl group. Preliminary structure-activity relationship points that unprotected OH group at C-1 and C-2 is not necessary to the antiparasitic activity, and none of the derivative was less active than lycorine. The lycorine structural requisites required to kill this amitochondriate cell seem to be different in comparison with the derivatives most active against other parasites and tumor cell lines, both mitochondriated cells. This result is an important contribution with our ongoing studies regarding the mechanism of action of the Amaryllidaceae alkaloids on T. vaginalis cell death opening a new perspective to optimize this innovative pharmacological potential.

Anti-Trichomonas vaginalis activity of synthetic lipophilic diamine and amino alcohol derivatives.

Taking in account the increased prevalence of metronidazole-resistant infections, alternative drugs are necessary for the treatment of trichomonosis. We report in this work the preparation and the in vitro anti-trichomonads activity of two diamines 1 and 2, and three different lipophilic amino alcohol derivatives 3, 4 and 5. These compounds were tested for in vitro activity against two isolates of Trichomonas vaginalis and displayed inhibition of the parasite growth. Five concentrations of each compound were tested. The butanediamine derivative 1, at a final concentration of 5.85 microM, presented a cytotoxic effect against 47% of T. vaginalis trophozoites. Furthermore, the cytotoxicity of 1 did not present statistically significant difference when compared to metronidazole in the same range of concentration (0.1-1.5 microg/mL).

Optimization and validation of an alternative method to evaluate total reactive antioxidant potential.

The total reactive antioxidant potential (TRAP) is one of the methods most employed to estimate the antioxidant capacity of samples in vitro. This method is based on the quenching of luminol-enhanced chemiluminescence derived from the thermolysis of 2,2'-azo-bis(2-amidinopropane)dihydrochloride (AAPH) as the free radical source. However, this method can present limitations when the sample does not present a lag phase. In addition, there are no studies regarding TRAP assay validation. In this context, the aim of this work was to optimize and validate this method and to propose another evaluation method using the area under the curve (AUC). The main condition established was the need for the stabilization of the system, at 7000s, before the addition of the antioxidant to be tested. Both evaluation methods were validated using Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) as a calibrator in the range of 50 to 250nM, and all parameters showed satisfactory results: specificity, linearity (r>0.99), precision (intra and interassay relative standard deviations <5%), robustness, and the limits of detection and quantitation (low and similar for both methods). The main advantage of the use of AUC is to evaluate the antioxidant potential of samples that do not present lag phase.

Análise de metais pesados em amostras de Peumus boldus Mol. (Monimiaceae) / Analysis of heavy metals in samples of Peumus boldus Mol. (Monimiaceae)

Oito amostras, provenientes do Brasil, Chile e Argentina, de Peumus boldus Molina (Monimiaceae), espécie comum e abundante no Chile, cujas folhas são amplamente empregadas pela medicina tradicional para o tratamento de uma variedade de afecções do sistema digestivo e hepatobiliar, foram analisadas, após digestão nítrica, para a quantificação de ferro, manganês, cobre, chumbo, cromo, cobalto e níquel, por espectrofotometria de absorção atômica. Chumbo, cromo e cobalto não foram detectados (limite de detecção de 5 µg/g) em nenhuma das amostras. Todas as amostras apresentaram maior teor em ferro, que variou de 109,7 mg/kg a 315,7 mg/kg, seguido por manganês (65,5 mg/kg a 158,8 mg/kg), cobre (3,04 mg/kg a 9,16 mg/kg) e níquel (0,77 mg/kg a 4,31 mg/kg).

Eight samples, obtained from Brazil, Chile and Argentina, of Peumus boldus Molina (Monimiaceae), an abundant and widespread native tree in Chile, which leaves are widely used in folk medicine for the treatment of digestive and hepatobiliary disorders, were analyzed, after nitric digestion, for the content of iron, manganese, copper, lead, chromium, cobalt and nickel, by atomic absorption spectrophotometry. Lead, chromium and cobalt were not detected (detection limit of 5 µg/g) in any sample. The samples showed a high level of iron, which ranged from 109.7 mg/kg to 315.7 mg/kg, followed by manganese (65.5 mg/kg to 158.8 mg/kg), copper (3.04 mg/kg to 9.16 mg/kg) and nickel (0.77 mg/kg to 4.31 mg/kg).